What Is a Blow Molding Machine?
A blow molding machine is a device used for plastic processing. It involves melting resin through heat, transferring it to a mold, blowing gas into the resin, cooling it, and shaping it into a product with a hollow interior. This processing method is commonly used for molding hollow bottles and containers.
There are three primary molding methods:
- Extrusion Method: In this method, the resin is heated to a liquid state and formed into a hollow pipe using an extrusion screw. It is then extruded into a mold, which is the key process used in blow molding machines.
- Injection Method: The injection method involves pre-filling a mold that can accept air, moving it to another mold, and then using air pressure to cool and shape it. This approach results in a two-step processing method known for its high dimensional accuracy.
- Stretching Method: The stretching method processes resin by blowing air through an air outlet after stretching it during the extrusion process, providing higher strength compared to other blow molding methods.
Uses of Blow Molding Machines
Blow molding machines find applications in the production of containers for storing liquids. Examples include plastic bottles, condiment containers, and plastic containers for medicines and pharmaceuticals. When selecting a blow molding machine, it’s essential to consider the processing method that best suits the product, as well as factors like price, size, production speed, and the percentage of defective products manufactured.
Principle of Blow Molding Machines
The operating principles of blow molding machines revolve around the extrusion, injection, and stretch methods. These machines typically consist of a heating section for melting resin, a mold, an air outlet, a cooling system, and mechanisms for moving resin and other materials through the various processes.